Rock bit



UNITED STATES PATENT` OFFICE.

`COLUMBUS, omo, AssIGNoR or' omi-HALF 'ro CLARENCE c.

CLINTON E. BULL, F

LE HAY,

0I' COLUMBUS, OHIO.

ROCK BIT.

[Application iled August 4, 1925. Serial lo. 48,065.

The present invention provements 1n rock bits is directed to irnfor oilwell drills.

The primary object of the invention is A further object of provide abearing of th structed that after becoming provide a compact and stoutbearing -for rock bits of the rolling type.

the invention is to is character so convvorn, which is a common defectin devices of this kind, the bearing can be easily and quickly adjustedto compensate for any Wear whic takes place.

A still further object to provide a bearing constructed and arrang ofthe invention is of this kind with means ed in such manner that theentrance of Water and afrit to the bearing is positively pr evented andits detrimental effect eliminated, thus eliminating; the normal wear ofparts to a minimum.

qWith these and other invention resides in construction, formationarrangements of parts objects in view this the novel features ofcombination and to be hereinafter more fully described, claimed andillustrated in the accompanying drawings, in Whichj- Figure 1 is afragmentary side elevation of the device.

Figure 2 is a transverse sectional view through one of the bits Figure 3is a sectional vien7 on line '3-3 of Figure 2.

Figure 4 is an end View of the bits, shown diagrammatically.

Figure 5 is a View of the bottom of the hole, showing diagrammaticallythe manner of cutting.

The drill head 1 is of complementary sections formed from a pair 2,bolted together,

as is customary, and are provided at their opposed beveled lower stubshafts 3, which duced extensions 4, ther ing passages 5 in said shafts,

which will appear later.

ends with threaded are provided with ree being oil conductthe purpose ofEach roller bit 6 is provided with a comparatively large recess v8 andin which the 7 and counter-bore bushing 9 is received.

These bushings are each provided with a head 10 and an integrallyconnected tapered extension 11 gage, respectively,

which is adapted to snugly eninthe recess 7 and coun'- ier-bore 8, itbeing essential that the inner end of the extension does not contactwith the base of the counter -bore to permit adsage 15 in the respectivesection 2. -In this manner proper lubricant of the bearing is assured.

The head 10 is provided' with radial slots 16, preferably'four innumber, said slots having opposed beveled Walls 17 and 1S to provideoppositely disposed fulcrums 19 upon which thev clamping plates 20 areadapt- I ed to rock when adjustments are made. The

inner ends of the slots ,open in the socket 13 whiletheir outer endscoincide with the annular groove 21 -formed in the inner periphery ofthebit 6. Thus it will be seen that the plates can be convenientlyinserted. in the slots 16 from the socket 13 or removed therefrom Whendesired.

The plates are provided Jwith seats 22 for engagement with the innerends of the locked set screws 23 carried by the head-10. It will beobserved that since the outerends of the plates rest in the groove 21inward movement of thesetn screws 23 will rock the plates on thefulcrums 1 9 andas the parts Wear 'such Wear can be compensated for uponsimply adjusting the set screws.v It will be further observed that'theplates 2() not' only serve as means for adjusting the bearing but alsoconstitutes means for rotatably interlocking-the bearing with the bit 6.

l To prevent any foreign matter from entering the bearing, a metallicpacking ring 24 is employed and engages in the groove 25 of the head10.A

In order to interlock'jthe bitv l6 and stub shaft 9 .so that they may beremoved or replaced upon the stub shaft 3 the` bit' is tapped, as at 26for the reception of the threaded end of the bar 27, the inner end ofwhich engages the socket 28 formedV in the head 10. In this manner thevbearing shafts can be conveniently removed from' the stub shafts, thetapped opening bein afterwardsplugg'ed to prevent entrance' o foreignmatter.

. cutting ribs 'of the bit following,

Upon reference to Figure 4A of the drawings, it will be observed thatthe ribs 28 of the bits are spirally arranged upon their cutting facesso; that when the bits roll, during their cutting operation, the linesof cutting'of one -bit will be intersected by the thus chipping the rockinto diamond formation, as shown in Figure 5. IThusthe rock at thebottom of the hole will be eiectively and quickly chipped."

It will be obvious that a bearing for bits of this nature constructed inaccordance with my invention will be extremely strong and since wear canbe compensated for, wobblin ofthe bits resulting from wear is eliminatethereby eliminating the -objectionable feature of drilling a hole of'Auneven diameter, which is often caused by bits rollingI on worn @urinesL What is claimed is 1. The combination with a rotary drill head, ofstub shafts carried thereby, bushings ixed to the stub shafts, bitsrotatably enga ed upon the bushings, plates interlocking t e b1ts andbushings, and means for rocking the' plates to take up wear between thebits and bushings.

2. The combination with a rotary drill head, of a stubl shaft carriedthereby, -a bush ing fixed t0 the "stub shaft, the bushin having slotsformed therein, plates rocka le in the slots andengaged with a bitrotatable bit and bushin and' means' carried by the bushing, for rorinthe plates to relatively adjust the bit and u sliin A 3. The combinationwil 'a rotary drill head, of a stub 'shaft carried thereby, a bushvandmeans for 'rockin l to rock Jthe same,

said plates: interlocking the Leonesa ing engaged with the` stub shaft,a bit rotatably engaged upon the bushing, and

bearing shafty and ro.

plates rockable in the tatably interlocking the bit and body, as and forthe purpose set forthn The combination with a rotary drill head, of astub shaft carried thereby, a bushing engaged with the stub shaft, a bitrotatable on the bushing, plates rockable in the bushing, said platesbeing adapted to rotatably interlock the bits with the bushing,

the plates to relatively adjust the bit and ushing.

5 The combination with a. rotary drill heayd, of a stub shaft carriedthereby, a relatively large bushing fixed tothe Vstub shaft, a bitrotatable on the bushing and having an annular loove formed therein,plates rockable in ge bushing and having their outer ends slidabl andAmeans carrie gagement with the engaged in the groove, by the'bushing foreninner ends of the plates as and for the purpose set forth.

6. The combination with a. rotary drill head,of stub shafts carriedthereb bushings detachably engaged upon t e stub shafts, roller bitsengaged upon the bushings Aand having annular grooves formed therein,said bushing havin radial slots formed therein coinciding with saidgrooves, plates rockable in the grooves and havin their outer endsslidably en aged with thev grooves, a set screw carried y the bushingand engaged with the inner ends of the plates to rock the same torelatively adjust the bushings and bits.

In. testimony whereof I aflix my signature.

^ CLINTONv H. BULL.

